trajectory_supervisor.supervisor_modules.supmod_friction.src.check_friction module

trajectory_supervisor.supervisor_modules.supmod_friction.src.check_friction.friction_check(ego_data: numpy.ndarray, a_lon_max_tires: float, a_lat_max_tires: float, dyn_model_exp: float = 2.0, drag_coeff: float = 0.0, m_veh: float = 1000.0) → tuple[source]

This function asses the trajectory safety for a given time instance regarding friction limit.

Parameters

  • ego_data – data of the ego vehicle(s, pos_x, pos_y, heading, curvature, velocity, acceleration) for a given time instance

  • a_lon_max_tires – maximal allowed longitudinal acceleration the ego vehicle can transfer via the tires

  • a_lat_max_tires – maximal allowed lateral acceleration of the ego vehicle can transfer via the tires

  • dyn_model_exp – exponent used in the vehicle dynamics model (usual range [1.0, 2.0]) NOTE: 2.0 represents a ideal friction circle; 1.0 a perfect diamond shape

  • drag_coeff – drag coefficient incl. all constants (0.5 * c_w * A_front * rho_air) [in m2*kg/m3] NOTE: set to zero, in order to disable drag consideration

  • m_veh – vehicle mass (required for drag calculation) [in kg]

Returns

  • safety - boolean value - ‘False’ for unsafe, ‘True’ for safe

  • safety_parameters - parameter dict (here: currently used acceleration and acceleration limit at value in trajectory, at position where the requested acceleration is closest to the bounds)

Authors
Created on

30.07.2019